Paul - do you have any ties to the STL MO area? We are all pork steak lovers around here. I don't usually marinate pork steaks. I am a big fan of dry brining these things, and usually just put a nice thick coat of my favorite BBQ rub on them and stick them in the fridge for up to 8 hours before I cook them. Make sure your rub has a good amount of salt for this method or it won't work as well.
You could also wet-brine, per directions on Morton's kosher salt box. Brine longer for thicker steaks and shorter for thin ones. Take em' out of the brine, pat dry, then put a little (not a lot) of your favorite seasononing on there. Be careful with adding more salt, because brining adds the salt. If you're going for bbq flavor you might want to whip up a homemade basic salt free bbq rub. Just about all of the store bought rubs I'm familiar with have a fair amount of salt.
Here's some pics of the ones I made using the dry brine method back in April;
Using direct and indirect heat - charring a bit on the right side, then finishing covered on the left on the PK360
Here's what they looked like just before I took them off. I probably had them covered and running about 350F for 15 to 20 minutes after charring them a bit. These pork steaks were about 3/4" thick. 1/2" or thinner, I'd cook 100% direct and wouldn't bother finishing indirect.